This invention relates to means to provide a retainer which fits inside the paper filter of a coffee filter receptacle to hold the paper filter walls in place against the supporting receptacle to prevent the collapse or folding over on itself of the paper filter which occurrence allows coffee grounds to find their way into the brewed coffee.
In the past, paper coffee filters have depended on the folds of the side walls of the filter to be of sufficient rigidity to support itself and lay against the walls of the filter receptacle, however, as the moisture of the hot water enters the filter, often times the filter will collapse as it becomes more pliable and can fold and lay upon itself allowing the coffee grounds to pass over the sides of the filter and enter the pot or vessel of the finished coffee thereby making an unsatisfactory situation as the brewed coffee now contains coffee grounds.
Sandrig in patent No. 4,728,425, addresses this problem by providing a filter apparatus which involves a custom made basket for holding an annular retainer which has a non-perforated, vertically extending wall portion with a plurality of openings adjacent to the retainer bottom edge for permitting liquid to and from within the confines of the retainer. It will readily be seen that this retainer will fit only it's own custom made basket and is not adaptable to fit coffee makers in general. Also this system allows filtration to occur only in designated places and does not use the entire surface of the filter which is available for filtering purposes.
The purpose of our invention is to provide a simple, effective means to hold the filter walls in an upright position by means of a universal retainer which is adaptable to most any coffee basket or apparatus.
A further purpose is to provide a simple retainer which allows all of the surface of the filter to be utilized for filtering purposes.
Still another purpose is to provide a filter retainer which is adjustable.
Another purpose is to provide a retainer which is sanitary and easily kept clean by conventional methods.
Other advantages and meritorious features of the present invention will be more fully understood from the following description of the drawings and the preferred embodiments, the claims and the detailed drawings which are described hereinbelow.